Effect of multi-walled carbon nanotubes with different diameters on morphology and thermal and mechanical properties of flexible polyurethane foams

2021 ◽  
pp. 026248932110172
Author(s):  
Fukai Yang ◽  
Miao Xie ◽  
Zhang Yudi ◽  
Xinyu Xu
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
In Situ Polymerization ◽  
Loss Modulus ◽  
Polyurethane Foams ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Different Diameters ◽  
Flexible Polyurethane ◽  
Walled Carbon Nanotubes

We report flexible polyurethane foams (PUFs) containing –OH functionalized multi-walled carbon nanotubes (MWCNTs) with different diameters (10–20 nm, 20–30 nm, >50 nm) from 0.1–0.6 wt% (per 100 resins of polyol by weight) prepared via in situ polymerization. After synthesis, the morphology of the MWCNT/PUF composites was observed through scanning electron microscopy (SEM) based on MWCNT amount. The MWCNTs acted as nucleating agents and increased the matrix viscosity. The pore size of the composites decreased and the number of pores increased with increasing MWCNT concentration. Dynamic mechanical analysis (DMA) showed that the storage modulus of the composites increased, the loss modulus decreased, and the Tg gradually decreased with increasing MWCNT content. The incorporation of MWCNTs induced remarkable thermal stabilization of the matrix. The increase in the degradation temperature from 294°C to 304°C resulted in a 50% weight loss. The mechanical properties of the MWCNT/PUF materials increased with increasing MWCNT proportion because of the excellent compatibility and strong interface interaction between the MWCNT and flexible PUF.

Polyethylene Functionalized Multi-Walled Carbon Nanotubes via In Situ Polymerization

2012 ◽  
Vol 573-574 ◽  
pp. 1163-1166
Author(s):  
Shi Yun Li ◽  
De Sheng Hu
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Storage Modulus ◽  
Raman Spectra ◽  
In Situ Polymerization ◽  
Thermal And Mechanical Properties ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The MWNTs/PE nanocomposites are prepared by in situ polymerization with mulltiwalled carbon nanotubes (MWNTs) supported Cp2ZrCl2 catalyst and MAO as cocatalyst. The SEM and AFM results show that MWNTs are exfoliated and homogenously dispersed in PE matrix by the in situ polymerization. The up-shifting of the G band in Raman spectra show the strong compressive forces associated with PE chains on the MWNTs. The storage modulus of the MWNTs/PE nanocomposite can be increased by 160% even at low amount of MWNTs (0.2 wt %) due to MWNTs well-dispersed and exfoliated in the matrix. The TGA and DMA tests point to significant improvements on thermal and mechanical properties of the PE/MWNTs nanocomposites compared to pure PE.

The Improvement of Mechanical Properties of Polyurethane Coating by Multi-Walled Carbon Nanotubes

2011 ◽  
Vol 236-238 ◽  
pp. 2063-2066
Author(s):  
Xian Kai Jiang ◽  
Ji You Gu ◽  
Yan Hua Zhang
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
In Situ Polymerization ◽  
Impact Resistance ◽  
Polyurethane Coating ◽  
Polyurethane Coatings ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Better Than

Mechanical properties of polyurethane coating were improved by multi-walled carbon nanotubes (MWNTs) via in situ polymerization and blending polymerization. Fourier transform infrared spectroscopy (FT-IR) measurement was employed to assess the influence of acid treatment on MWNTs. Mechanical properties analysis of polyurethane coatings including tensile strength, elastic modulus, hardness, flexibility, impact resistance were employed to assess the improvement of mechanical properties of polyurethane coating by MWNTs. The results indicated that MWNTs could improve the mechanical properties of polyurethane coatings, and the improvement of polyurethane coatings by MWNTs via in situ polymerization were better than via blending polymerization, and the improvement of polyurethane coatings by acid-treated MWNTs were better than by raw MWNTs.

Preparation and Properties of Polyimide/MWNTs-COOH Antistatic Composites

2014 ◽  
Vol 893 ◽  
pp. 241-244
Author(s):  
Yong Hui Lv ◽  
Bao Xiang Deng
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Acid Treatment ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Good Thermal Stability ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The acidified multi-walled carbon nanotubes (MWNTs-COOH) was obtained by nitric acid treatment on multi-walled carbon nanotubes (MWNTs).The PI/MWNTs-COOH composite films were synthesized by in situ polymerization. The thermal stability, resistance and mechanical properties of PI/MWNTs-COOH composite were evaluated. The results showed that: the composites maintained a good thermal stability with the addition of the MWNTs-COOH; the resistance of the composite film dropped at first, and rose up later. While the tensile strength increased at first and then decreased. In conclusion, the PI/MWNTs-COOH composite films exhibited better thermal, antistatic and mechanical properties compared with neat PI.

Mechanical properties and interfacial phenomena in aluminum reinforced with carbon nanotubes manufactured by the sandwich technique

2016 ◽  
Vol 51 (11) ◽  
pp. 1619-1629 ◽  
Author(s):  
Cesar A Isaza M ◽  
JE Ledezma Sillas ◽  
JM Meza ◽  
JM Herrera Ramírez
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Metallic Matrix ◽  
Sandwich Technique ◽  
Open Questions ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Matrix Reinforcement ◽  
Walled Carbon Nanotubes

Recently, a new manufacturing process for the production of metallic matrix composite materials reinforced with carbon nanotubes, known as sandwich technique has been proposed. This technique produces a material comprised of a metallic matrix and a banded structures-layers of multi-walled carbon nanotubes. However, among other issues, the matrix-reinforcement interface and the reinforcement dispersion degree are still open questions. The present study uses field emission scanning electron microscopy and high resolution transmission electron microscopy to probe that the method is capable to achieve a good dispersion of the multi-walled carbon nanotubes with no evidence of carbon nanotubes’ damage. The mechanical properties were measured by tensile and nanoindentation tests; improvements in the elastic modulus, yield and ultimate strengths were found, with respect to the unreinforced material.

Effect of carbon nanotube modification on poly (butylene terephthalate)-based composites

2016 ◽  
Vol 70 (6) ◽  
Author(s):  
Agnieszka Piegat ◽  
Anna Jędrzejewska ◽  
Robert Peƚech ◽  
Iwona Peƚech
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Lower Amount ◽  
Butylene Terephthalate ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Modified Carbon Nanotubes ◽  
Walled Carbon Nanotubes

AbstractThe influence of the chemical modification of carbon nanotubes on the mechanical, thermal and electrical properties of poly(butylene terephthalate)-based composites was investigated. Polymer composites based on poly(butylene terephthalate) were obtained via in situ polymerisation or extrusion. Commercially available multi-walled carbon nanotubes (Nanocyl NC7000) at different loadings (mass %: 0.05, 0.25, 1, 2) were used as fillers. The functionalisation process took place under a chlorine atmosphere followed by a reaction with sodium hydroxide. The effect of carbon nanotube modification was analysed according to the changes in the polymer thermal and mechanical properties. An addition of modified carbon nanotubes in the amount of 0.05 mass % improved the mechanical properties of the composites in terms of both Young’s modulus and tensile strength by 5–10 % and 17–30 % compared with composites with unmodified carbon nanotubes and neat poly(butylene terephthalate), respectively. The in situ method of composite preparation was a more effective technique for enhancing the matrix–filler interactions, although a significantly lower amount of fillers were used than in the extrusion method.

Influence of Multi-Walled Carbon Nanotubes on the Mechanical Properties of Nanocomposites

2010 ◽  
Vol 139-141 ◽  
pp. 9-12 ◽  
Author(s):  
Shiuh Chuan Her ◽  
Shun Wen Yeh
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Matrix Stiffness ◽  
Mixture Ratio ◽  
Hardness Tests ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The effects of matrix stiffness and the content of multi-walled carbon nanotubes on the mechanical properties of the nanocomposites have been examined in this investigation. The matrix stiffness was controlled by changing the mixture ratio between the epoxy and hardener. Two different contents (1 wt.%. and 2 wt.%) of the multi-walled carbon nanotubes (MWCNT) were added to the epoxy matrix. Three-Point-Bending and Shore’s hardness tests were conducted to determine the Young’s modulus and hardness of the nanocomposites, respectively. Experimental results showed that the Young’s modulus of the nanocomposites was significantly increased with the increase of the addition of MWCNTs. However, the improvement of the hardness of the epoxy was insignificant with the addition of the MWCNTs. The reinforcement role of the multi-walled carbon nanotubes decreased while increasing the stiffness matrix.

scholarly journals Enhancement of out-of-plane mechanical properties of carbon fiber reinforced epoxy resin composite by incorporating the multi-walled carbon nanotubes

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Seyed Ali Mirsalehi ◽  
Amir Ali Youzbashi ◽  
Amjad Sazgar
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Test ◽  
Epoxy Resin ◽  
Laminate Composite ◽  
Filament Winding ◽  
Hybrid Nanocomposites ◽  
Out Of Plane ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

AbstractIn this study, epoxy hybrid nanocomposites reinforced by carbon fibers (CFs) were fabricated by a filament winding. To improve out-of-plane (transverse) mechanical properties, 0.5 and 1.0 Wt.% multi-walled carbon nanotubes (MWCNTs) were embedded into epoxy/CF composites. The MWCNTs were well dispersed into the epoxy resin without using any additives. The transverse mechanical properties of epoxy/MWCNT/CF hybrid nanocomposites were evaluated by the tensile test in the vertical direction to the CFs (90º tensile) and flexural tests. The fracture surfaces of composites were studied by scanning electron microscopy (SEM). The SEM observations showed that the bridging of the MWCNTs is one of the mechanisms of transverse mechanical properties enhancement in the epoxy/MWCNT/CF composites. The results of the 90º tensile test proved that the tensile strength and elongation at break of nanocomposite with 1.0 Wt.% MWCNTs improved up to 53% and 50% in comparison with epoxy/CF laminate composite, respectively. Furthermore, the flexural strength, secant modulus, and elongation of epoxy/1.0 Wt.% MWCNT/CF hybrid nanocomposite increased 15%, 7%, and 9% compared to epoxy/CF laminate composite, respectively.

Study of Rheological Properties of Carbon Nanotube-Reinforced Ultrafine Cement Grouting Materials

2021 ◽  
pp. 1-44
Author(s):  
Yunxiao Liu ◽  
Jiahang Zhang ◽  
Yinyin Chi
Keyword(s):  
Carbon Nanotubes ◽  
Rheological Properties ◽  
Polyvinyl Pyrrolidone ◽  
Cement Grouting ◽  
Grouting Material ◽  
Multi Walled Carbon Nanotubes ◽  
Different Diameters ◽  
Grouting Materials ◽  
Walled Carbon Nanotubes ◽  
Ultrafine Cement

In this study, three different diameters of multi-walled carbon nanotubes (MWCNTs) dispersed by polyvinyl pyrrolidone (PVP) were used to reinforce superfine cement grouting materials. The effect of MWCNTs and polyvinyl pyrrolidone (PVP) on the rheological properties of grouting material were accordingly studied. It was found that the yield stress (τ0) and plastic viscosity (η) were slightly decreased when PVP content was low and increased when the PVP content increased. The effect of MWCNT diameter on τ0 was not found to be clear but was more significant on η. The smaller MWCNT diameter was, the more quickly η increase. It was also found that the thixotropic ring area was increased as the MWCNTs content increased. The addition of PVP and MWCNTs caused an increase in the number of entanglement points in different scales, which was the main reason for the viscosity and thixotropy increase. Therefore, the rheological properties of superfine cement grouting material should be adjusted when MWCNTs were added as a reinforcing component. Due to the wrapping of PVP on cement particles which isolates the contacting part between the water and the cement particles, it slows down the cement's hydration rate thus slows down the fluidity loss of the slurry.

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